Collapsible dispensers for soap and other fluids are known as for use, for example, in fluid dispensers such as that taught by the applicant's U.S. Pat. No. 5,836,482 entitled Automated Fluid Dispenser, issued Nov. 17, 1998, the disclosure of which is incorporated herein by reference. While the collapsible container may comprise a flexible bag which is not self-supporting, preferred collapsible containers comprise containers which are self-supporting as when filled with material yet are provided to collapse upon themselves. Such a collapsible container is, for example, illustrated in the applicant's U.S. Design Patent 350,070 and in FIG. 1 of U.S. Pat. No. 5,836,482 as comprising a bottle having a generally rectangular cross-section with side walls with folds provided therein such that opposing side walls become bent inwardly in a pleated manner towards each other facilitating the movement of opposite side walls inwardly towards each other.
A disadvantage of previously known collapsible containers is that the containers sometimes collapse in a manner which traps fluid therein. For example, whether a self-supporting container or a bag-like container, the collapsible container may collapse prematurely at an intermediate portion with the collapse at the intermediate portion preventing withdrawal from the container as from an outlet disposed at the bottom of the container of material in the container spaced from the outlet by the prematurely collapsed intermediate portion. This disadvantage is particularly acute when the fluid to be dispensed is expensive or under circumstances where the dispensing of fluid is critical to be maintained.